Roll-molding device

ABSTRACT

For a tapered material having a plate thickness changing in a longitudinal direction to be roll-molded with stability by means of a simple and inexpensive configuration, a roll-molding device includes two parallel roller shafts, fixed rollers concentrically disposed with respect to one of the roller shafts, floating rollers disposed to be capable of being eccentric with clearances with respect to the other one of the roller shafts, facing the fixed rollers, and molding a belt-shaped metallic material pinched between the fixed rollers and themselves, a pressing roller abutting against an outer circumferential portion on the side opposite to points of contact of the floating rollers with the fixed rollers, and actuators pressing the floating rollers toward the fixed rollers via the pressing roller.

TECHNICAL FIELD

The present invention relates to a roll-molding device that sends a belt-shaped metallic material to a space between a plurality of sets of molding rollers and molds a sectional shape of the metallic material into a predetermined shape and, more particularly, to a roll-molding device that is capable of responding even to a case where a plate thickness of the metallic material changes.

BACKGROUND ART

Molding is performed in stages through a plurality of molding processes illustrated in FIGS. 1B to 1J in a case where, for example, a flat belt-shaped metallic material M illustrated in FIG. 1A is molded into an aircraft stringer member S or the like that has a bent sectional shape illustrated in FIG. 1 k.

The plurality of molding processes is performed by a roll-molding device, in which a plurality of sets of molding rollers with different sectional shapes is arranged on a line called a roll forming line as illustrated in FIG. 9 of PTL 1. The metallic material M is molded in stages as it passes between the plurality of sets of molding rollers arranged in the roll-molding device.

In the roll-molding device according to the related art, each of the molding rollers is concentrically disposed with respect to a roller shaft, that is, disposed such that an axial center with respect to a roller shaft does not change.

CITATION LIST Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 7-29146

SUMMARY OF INVENTION Technical Problem

These days, stringer members for aircraft are given the shape of what is called a tapered stringer as illustrated in FIG. 2B as a result of molding by means of a tapered material M′ that has a plate thickness changing in a tapered shape along a longitudinal direction as illustrated in FIG. 2A. This tapered stringer TS is to achieve lightweightness by maintaining a large plate thickness Tmax at a part combined with another airframe member and maintaining a minimized plate thickness Tmin at another part.

Required when the tapered material M′ is molded by the roll-molding device disclosed in PTL 1 is control for lifting and lowering a molding roller abutting against an uneven surface of the tapered material M′ with a roller shaft by means of a servomotor or the like for the uneven shape to be followed. Accordingly, problems arise in the form of the roll-molding device becoming complex in configuration and costly.

The present invention has been made in view of such circumstances, and an object thereof is to provide a roll-molding device that is capable of performing roll molding with stability on a tapered material which has a plate thickness changing in a longitudinal direction by using a simple and inexpensive configuration.

Solution to Problem

In order to address the above problem, the present invention adopts the following means.

A roll-molding device according to the present invention includes two parallel roller shafts, a fixed roller concentrically disposed with respect to one of the two roller shafts, a floating roller disposed to be capable of being eccentric with a clearance with respect to the other one of the two roller shafts and facing the fixed roller, a pressing roller abutting against an outer circumferential portion on the side opposite to a point of contact of the floating roller with the fixed roller, and an actuator pressing the floating roller toward the fixed roller via the pressing roller.

In the roll-molding device that has the above-described configuration, a belt-shaped metallic material is sent to a space between the fixed roller concentrically disposed on the roller shaft and the floating roller disposed to be capable of being eccentric on the other roller shaft and the actuator presses the floating roller toward the fixed roller via the pressing roller. Accordingly, a sectional shape of the metallic material is molded in accordance with shapes of the fixed roller and the floating roller.

Even if, for example, the metallic material is a tapered material that has a plate thickness changing in a tapered shape along its longitudinal direction, the floating roller becomes eccentric with respect to the roller shaft in response to that change in the plate thickness of the metallic material. As a result, a difference in plate thickness is absorbed.

At this time, a pressing force of the actuator is given to the floating roller itself via the pressing roller and is not given to the roller shaft where the floating roller is disposed. Accordingly, the metallic material can be molded into a predetermined shape with a constant pressing force given regardless of an eccentric position of the floating roller with respect to the roller shaft, that is, regardless of the plate thickness of the metallic material.

Accordingly, it becomes unnecessary to lift and lower both a molding roller and a roller shaft by means of a servomotor or the like as in the related art, and the tapered material that has the plate thickness changing in the longitudinal direction can be roll-molded with stability by the use of the very simple and inexpensive configuration.

In the above-described configuration, the pressing roller is disposed in a distributed manner at a plurality of symmetrical positions across an axial center connecting line, which connects axial center lines of the two roller shafts to each other, in axial view of the two roller shafts.

According to this configuration, the pressing force of the actuator is equally given to the floating roller from the plurality of pressing rollers disposed at the symmetrical positions across the axial center connecting line. Accordingly, a radial escape of the positions of the pressing roller and the floating roller that is attributable to the pressing force of the actuator can be prevented, and the metallic material can be roll-molded with stability with the pressing force of the actuator reliably given to the floating roller.

In the above-described configuration, the plurality of pressing rollers is pivotally supported by a common roller carrier and the actuator presses a position of intersection of the roller carrier with the axial center connecting line in the axial view of the two roller shafts.

According to this configuration, intermediate points of the plurality of pressing rollers disposed at the symmetrical positions across the axial center connecting line are pressed by the actuator. Accordingly, the pressing force of the actuator can be equally given to the plurality of pressing rollers and the floating roller can be pressed with stability.

The above-described configuration may also include a pair of guide rollers abutting against the outer circumferential portion of the floating roller and pivotally supported on both sides of the axial center connecting line across the axial center connecting line connecting the axial center lines of the two roller shafts to each other within a range between a pivotal support position of the roller shaft where the floating roller is disposed and a pivotal support position of the pressing roller.

According to this configuration, the floating roller is held from both outer sides in a radial direction by the pair of guide rollers when the pressing force of the actuator is given to the floating roller via the pressing roller. Accordingly, the radial escape of the position of the floating roller that is attributable to the pressing force of the actuator can be prevented, and the pressing force of the actuator can be reliably given to the floating roller.

In the above-described configuration, a constant force changing only the sectional shape of the metallic material pinched between the fixed roller and the floating roller without impairing the plate thickness of the metallic material is set as the pressing force of the actuator.

Once the pressing force of the actuator is set as described above, the plate thickness of the metallic material is not impaired and the metallic material is roll-molded into a predetermined sectional shape with its originally planned plate thickness maintained even if the floating roller is pressed against the metallic material due to the pressing force of the actuator.

Accordingly, product quality can be improved without the plate thickness of each portion of the metallic material being impaired even if, for example, the metallic material is the tapered material that has the plate thickness changing in the tapered shape along its longitudinal direction.

In the above-described configuration, a plurality of sets of the fixed rollers and a plurality of sets of the floating rollers are disposed, the fixed roller and the floating roller are disposed adjacent to each other in an axial direction at each of the two roller shafts, the fixed roller disposed at each one of the roller shafts faces the floating roller disposed at the other one of the roller shafts, a plurality of recessed portions for driving lining up in a circumferential direction is formed in an adjacent surface of one of the fixed roller and the floating roller adjacent to each other and pivotally supported by one of the roller shafts and a plurality of projecting portions for driving loosely fitted into the recessed portions for driving is formed on the other adjacent surface, and an eccentricity margin allowing the floating roller to be eccentric is provided between the recessed portion for driving and the projecting portion for driving.

According to this configuration, a rotational force of the fixed roller integrally disposed on the roller shaft is transmitted to the floating roller by the fitting between the recessed portion for driving and the projecting portion for driving. Accordingly, the roll-moldability of the metallic material can be improved with the floating roller reliably driven to rotate without slipping.

Since the eccentricity margin allowing the floating roller to be eccentric is provided between the recessed portion for driving and the projecting portion for driving, the floating roller can be driven to rotate with eccentricity of the floating roller allowed. As a result, even the metallic material that has the changing plate thickness can be smoothly molded.

In the above-described configuration, a roller width of at least one of the fixed roller and the floating roller can be changed.

According to this configuration, the width of the fixed roller or the floating roller can match an inside dimension of the metallic material even if, for example, the metallic material has a sectional shape including a recessed portion which has a channel shape. Accordingly, the metallic material can be roll-molded with accuracy.

Advantageous Effects of Invention

With the roll-molding device according to the present invention, roll-molding can be performed with stability and by the use of the simple and inexpensive configuration as described above even on the tapered material that has the plate thickness changing in the longitudinal direction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a sectional view illustrating a molding process that continues until a flat belt-shaped metallic material is molded into an aircraft stringer member.

FIG. 1B is a sectional view illustrating the same metallic material molding process.

FIG. 1C is a sectional view illustrating the same metallic material molding process.

FIG. 1D is a sectional view illustrating the same metallic material molding process.

FIG. 1E is a sectional view illustrating the same metallic material molding process.

FIG. 1F is a sectional view illustrating the same metallic material molding process.

FIG. 1G is a sectional view illustrating the same metallic material molding process.

FIG. 1H is a sectional view illustrating the same metallic material molding process.

FIG. 1I is a sectional view illustrating the same metallic material molding process.

FIG. 1J is a sectional view illustrating the same metallic material molding process.

FIG. 1K is a sectional view illustrating the same metallic material molding process.

FIG. 2A is a perspective view illustrating a tapered material that has a plate thickness changing in a tapered shape along a longitudinal direction.

FIG. 2B is a perspective view illustrating the tapered stringer that is roll-molded by the tapered material in FIG. 2A being used.

FIG. 3 is a longitudinal sectional view of a roll-molding device according to an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of the roll-molding device taken along line IV-IV of FIG. 3.

FIG. 5 is a longitudinal sectional view of the roll-molding device illustrating a state reached in a case where the plate thickness of the metallic material has fallen below that illustrated in FIG. 3.

FIG. 6 is a longitudinal sectional view of the roll-molding device illustrating a state reached in a case where the plate thickness of the metallic material has exceeded that illustrated in FIG. 3.

FIG. 7A is a diagram illustrating an eccentric state of a floating roller in a case where the plate thickness of the metallic material has changed.

FIG. 7B is a diagram illustrating the eccentric state of the same floating roller.

FIG. 7C is a diagram illustrating the eccentric state of the same floating roller.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described with reference to accompanying drawings.

FIG. 3 is a longitudinal sectional view of a roll-molding device according to the embodiment of the present invention, and FIG. 4 is a longitudinal sectional view taken along line IV-IV of FIG. 3. FIG. 3 is a longitudinal sectional view taken along line III-III of FIG. 4.

This roll-molding device 1 is capable of, for example, easily molding a tapered material M′ (metallic material) illustrated in FIG. 2A, which has a plate thickness changing in a tapered shape along a longitudinal direction, into a tapered stringer TS illustrated in FIG. 2B. The roll-molding device 1 according to the present embodiment performs, for example, a final molding process on a roll forming line with a plurality of sets of molding rollers that has different sectional shapes arranged on the line. The roll-molding device 1 according to the present embodiment, however, is not limited to performing the final process and may also perform an initial molding process or an intermediate molding process. In addition, the roll molding may be performed on a single unit basis without being limited to the roll forming line.

As illustrated in FIG. 3, this roll-molding device 1 is provided with a base pedestal 2 positioned in a lower portion, a pair of left and right stands 3L and 3R standing from the base pedestal 2, and an upper beam 4 connecting upper end portions of the left and right stands 3L and 3R to each other.

Two horizontal, upper and lower, roller shafts 7A and 7B are rotatably installed via bearings 6 between the two stands 3L and 3R. Gears 8A and 8B, which are fixed to end portions of the two roller shafts 7A and 7B, are engaged with each other. By a rotational driving force R being given from a driving source such as an electric motor (not illustrated) disposed at the roller shaft 7A, which is one of the two roller shafts 7A and 7B, the two roller shafts 7A and 7B perform constant-speed interlocking rotation in directions of rotation that are opposite to each other. In other words, the roller shaft 7A is a driving shaft and the roller shaft 7B is a driven shaft.

Fixed rollers 11A and 11B are concentrically disposed on the roller shaft 7A and the roller shaft 7B, respectively. The fixed rollers 11A and 11B rotate integrally with the roller shafts 7A and 7B, respectively. For example, the upper fixed roller 11B is a stepped roller.

Floating rollers 12A and 12B are disposed, to be capable of being eccentric, on the roller shaft 7A and the roller shaft 7B, respectively. The floating rollers 12A and 12B are capable of rotating relative to the roller shafts 7A and 7B, respectively.

The fixed roller 11A and the floating roller 12A are disposed adjacent to each other in an axial direction on the roller shaft 7A, and the fixed roller 11B and the floating roller 12B are disposed adjacent to each other in the axial direction on the roller shaft 7B. The fixed roller 11A disposed on the roller shaft 7A faces the floating roller 12B disposed on the roller shaft 7B, and the fixed roller 11B disposed on the roller shaft 7B faces the floating roller 12A disposed on the roller shaft 7A. A spacer 13, which regulates a movement of the floating roller 12B in the axial direction, is axially mounted on the roller shaft 7B.

As illustrated in FIGS. 3, 5, and 6, the tapered material M′ (tapered stringer TS) is sent and molded between the fixed roller 11A and the floating roller 12B and between the floating roller 12A and the fixed roller 11B. The upper fixed roller 11B is the stepped roller as described above and an outer circumferential portion of the floating roller 12A is pinched between the fixed roller 11B and the floating roller 12B, and thus the tapered material M′ can be molded to be given, for example, a sectional shape bent in a crank shape (channel shape). In this case, the tapered material M′ is also pinched between a side surface of the floating roller 12A and a side surface of the floating roller 12B and between a side surface of the floating roller 12A and a side surface of the fixed roller 11B.

As illustrated in FIGS. 3 and 4, clearances CA and CB are provided between the roller shaft 7A and the floating roller 12A and between the roller shaft 7B and the floating roller 12B, respectively. The floating rollers 12A and 12B can be eccentric with respect to the fixed rollers 11A and 11B to the same extent as the clearances CA and CB. The clearances CA and CB need to have a size exceeding the difference between the maximum plate thickness and the minimum plate thickness of the tapered material M′. In a case where the tapered material M′ has a maximum plate thickness of 3 mm and a minimum plate thickness of 1 mm, for example, the clearances CA and CB are set to exceed the difference between the plate thicknesses, that is, 2 mm.

As illustrated in FIGS. 3 and 4, a plurality of recessed portions for driving 15 (eight being an example of the number thereof) that lines up in a circumferential direction is formed in one of surfaces of adjacency in a portion of adjacency between the fixed rollers 11A and 11B and the floating rollers 12A and 12B adjacent thereto, examples of which include side surfaces of the fixed rollers 11A and 11B.

Projecting portions for driving 16, which are loosely fitted into and equal in number to the recessed portions for driving 15 of the fixed rollers 11A and 11B, are formed on the other surface of adjacency in the portion of adjacency between the fixed rollers 11A and 11B and the floating rollers 12A and 12B, examples of which include side surfaces of the floating rollers 12A and 12B.

Eccentricity margins EA and EB, which allow the floating rollers 12A and 12B to be eccentric, are provided between the recessed portions for driving 15 and the projecting portions for driving 16. The eccentricity margins EA and EB have a size set to be substantially the same as that of the clearances CA and CB between the roller shafts 7A and 7B and the floating rollers 12A and 12B.

In the present embodiment, the recessed portions for driving 15 are formed on the fixed rollers 11A and 11B side and the projecting portions for driving 16 are formed on the floating rollers 12A and 12B side. However, the projecting portions for driving 16 may be formed on the fixed rollers 11A and 11B side with the recessed portions for driving 15 formed on the floating rollers 12A and 12B side as well.

A roller width W of the floating roller 12A, for example, can be changed. As illustrated in FIG. 3, the floating roller 12A is provided with two movable roller faces 12 a and 12 b that are movable in the axial direction, and sleeves 12 c and 12 d are integrally disposed on the respective movable roller faces 12 a and 12 b. A flange 12 e is disposed in an end portion of the sleeve 12 d on the side opposite to the movable roller face 12 b.

The sleeve 12 d is closely fitted, to be slidable in the axial direction, with an outer periphery of the sleeve 12 c. Relative sliding of the sleeves 12 c and 12 d in the axial direction results in a change in an axial gap between the movable roller faces 12 a and 12 b. As a result, the roller width W of the floating roller 12A changes.

An axial pressing force is given from a hydraulic device (not illustrated) to an end portion of the sleeve 12 c and the flange 12 e. For example, a constant force toward a side surface of the floating roller 12B is given in the axial direction to the end portion of the sleeve 12 c as illustrated by an arrow f1. A constant force toward a side surface of the fixed roller 11B is given in the axial direction to the flange 12 e as illustrated by an arrow f2.

This results in control by which the gap between the movable roller faces 12 a and 12 b is opened by the constant force at all times, that is, the roller width W of the floating roller 12A increases. The above-described clearance CA is provided between an inner peripheral surface of the sleeve 12 c and an outer peripheral surface of the roller shaft 7A and the floating roller 12A as a whole is allowed to be eccentric with respect to the fixed roller 11A.

On the floating roller 12A, the above-described projecting portions for driving 16 are formed on the movable roller face 12 b side and the projecting portions for driving 16 are loosely fitted into the recessed portions for driving 15 disposed in the fixed roller 11A through the movable roller face 12 a. Accordingly, once the roller shaft 7A and the fixed roller 11A rotate, the rotation is transmitted to the movable roller faces 12 a and 12 b through the fitting between the recessed portions for driving 15 and the projecting portions for driving 16. As a result, the floating roller 12A is driven to rotate.

As illustrated in FIG. 4, two pressing rollers 19 abut against the vicinity of each of outer circumferential portions of the floating rollers 12A and 12B on the sides opposite to respective points of contact with the fixed rollers 11A and 11B. In axial view of the two roller shafts 7A and 7B, for example, the pressing rollers 19 are disposed in a distributed manner at symmetrical positions across an axial center connecting line O connecting axial center lines C1 and C2 of the roller shafts 7A and 7B to each other.

Likewise, a pair of guide rollers 20 abutting against the outer circumferential portions to pinch the floating rollers 12A and 12B is disposed at positions where orthogonal lines L1 and L2, which are orthogonal to the axial center connecting line O and pass through the axial center lines C1 and C2 of the roller shafts 7A and 7B in the axial view of the roller shafts 7A and 7B, intersect with the outer circumferential portions of the floating rollers 12A and 12B. The pressing rollers 19 and the guide rollers 20 are pivotally supported by common roller carriers 21A and 21B.

The roller carriers 21A and 21B have a substantially semicircular shape that surrounds, for example, a lower half of the floating roller 12A and an upper half of the floating roller 12B in the axial view of the roller shafts 7A and 7B as illustrated in FIG. 4. The two pressing rollers 19 line up and are pivotally supported in a middle portion of each of the roller carriers 21A and 21B, and the guide rollers 20 are pivotally supported at both tip portions of the roller carriers 21A and 21B. In the present embodiment, both the two pressing rollers 19 and the two guide rollers 20 are symmetrically placed across the axial center connecting line O. However, these may not be completely symmetrical as well.

Also disposed are actuators 23A and 23B, which press the floating rollers 12A and 12B toward the fixed rollers 11A and 11B via the pressing rollers 19. A hydraulic cylinder, an air cylinder, or the like is used as the actuators 23A and 23B.

The actuator 23A is fixed to the base pedestal 2 and the actuator 23B is fixed to the upper beam 4. In the axial view of the two roller shafts 7A and 7B, the actuators 23A and 23B press positions of intersection of the roller carriers 21A and 21B with the axial center connecting line O with a pressing force F and in a direction along the axial center connecting line O, respectively.

Accordingly, intermediate points of the respective pressing rollers 19 are pressed toward the floating rollers 12A and 12B by the pressing force F of the actuators 23A and 23B.

A constant force that changes only the sectional shape of the tapered material M′ without changing its plate thickness is set as the pressing force F of the actuators 23A and 23B.

It is desirable that pivotal support positions (heights) of the guide rollers 20 are positions corresponding to the orthogonal lines L1 and L2 orthogonal to the axial center connecting line O and passing through the axial center lines C1 and C2 of the roller shafts 7A and 7B. Still, the guide rollers 20 may also be pivotally supported at positions closer to the pressing rollers 19 than those positions are. In other words, the guide rollers 20 may be pivotally supported on both sides of the axial center connecting line O across the axial center connecting line O within ranges Z1 and Z2 between the axial center lines C1 and C2 of the roller shafts 7A and 7B and the pivotal support positions of the pressing rollers 19 as illustrated in FIG. 4. Preferably, the pivotal support positions are positions separated to the maximum extent possible from the pressing rollers 19 within the ranges Z1 and Z2, that is, positions close to the orthogonal lines L1 and L2.

The roll-molding device 1 has the configuration described above. In a case where the tapered material M′ is molded, the tapered material M′ is sent to a space between the fixed roller 11A concentrically disposed on the roller shaft 7A and the floating roller 12A disposed to be capable of being eccentric on the roller shaft 7A and the fixed roller 11B concentrically disposed on the roller shaft 7B and the floating roller 12B disposed to be capable of being eccentric on the roller shaft 7B.

Then, the actuators 23A and 23B press the floating rollers 12A and 12B toward the fixed rollers 11A and 11B via the pressing rollers 19, respectively. As a result, the sectional shape of the tapered material M′ is subjected to final molding in accordance with the shapes of the fixed rollers 11A and 11B and the floating rollers 12A and 12B.

Although the plate thickness of the tapered material M′ changes in the tapered shape along the longitudinal direction, a difference in plate thickness is absorbed by the floating rollers 12A and 12B becoming eccentric with respect to the roller shafts 7A and 7B in response to that change in plate thickness.

In a case where the tapered material M′ has a basic plate thickness of T2 (such as 2 mm) as illustrated in FIGS. 3 and 7B, for example, the floating roller 12A(B) is concentric with respect to the roller shaft 7A(B).

In a case where the tapered material M′ has a plate thickness of T1 (such as 1 mm) that is smaller than T2 as illustrated in FIGS. 5 and 7A, the floating roller 12A(B) becomes eccentric with respect to the roller shaft 7A(B) in a direction in which the facing fixed roller 11B(A) is approached.

In a case where the tapered material M′ has a plate thickness of T3 (such as 3 mm) that exceeds T2 as illustrated in FIGS. 6 and 7C, the floating roller 12A(B) becomes eccentric with respect to the roller shaft 7A(B) in a direction in which it is separated from the facing fixed roller 11B(A).

At this time, the pressing force F of the actuators 23A and 23B is given to the floating rollers 12A and 12B themselves via the pressing rollers 19 and is not given to the roller shafts 7A and 7B where the floating rollers 12A and 12B are disposed. Accordingly, the tapered material M′ can be molded into a predetermined shape with a constant pressing force F given regardless of the eccentric positions of the floating rollers 12A and 12B with respect to the roller shafts 7A and 7B, that is, regardless of the plate thickness of the tapered material M′.

Accordingly, it becomes unnecessary to lift and lower both a molding roller and a roller shaft by means of a servomotor or the like as in the related art, and the tapered material M′ that has the plate thickness changing in the longitudinal direction can be roll-molded with stability by the use of the very simple and inexpensive configuration.

In this roll-molding device 1, the two pressing rollers 19 that press each of the floating rollers 12A and 12B are disposed in a distributed manner at the symmetrical positions across the axial center connecting line O in the axial view of the roller shafts 7A and 7B. Accordingly, the pressing force F of the actuators 23A and 23B is equally given to the floating rollers 12A and 12B from the two respective pressing rollers 19.

Accordingly, a radial escape of the positions of the pressing rollers 19 and the floating rollers 12A and 12B that is attributable to the pressing force of the actuators 23A and 23B can be further prevented than in a case where, for example, the floating rollers 12A and 12B are pressed with one pressing roller 19 disposed at a position corresponding to the axial center connecting line O. Accordingly, the tapered material M′ can be roll-molded with stability with the pressing force F of the actuators 23A and 23B reliably given to the floating rollers 12A and 12B.

In this roll-molding device 1, the two pressing rollers 19 pressing each of the floating rollers 12A and 12B are pivotally supported by the respective common roller carriers 21A and 21B and, in the axial view of the roller shafts 7A and 7B, the actuators 23A and 23B press the positions of intersection of the roller carriers 21A and 21B with the axial center connecting line O.

Accordingly, the intermediate points of the two pressing rollers 19 disposed at the symmetrical positions across the axial center connecting line O are pressed by the actuators 23A and 23B, and thus the pressing force F of the actuators 23A and 23B can be equally given to the plurality of pressing rollers 19 and the floating rollers 12A and 12B can be stably pressed.

In this roll-molding device 1, the pair of guide rollers 20 abutting to pinch the floating rollers 12A and 12B is also pivotally supported by the roller carriers 21A and 21B at the positions where the orthogonal lines L1 and L2, which are orthogonal to the axial center connecting line O and pass through the axial center lines C1 and C2 of the roller shafts 7A and 7B in the axial view of the roller shafts 7A and 7B, intersect with the outer circumferential portions of the floating rollers 12A and 12B.

Since the pair of guide rollers 20 is disposed, the floating rollers 12A and 12B are held from both outer sides in a radial direction by the guide rollers 20 when the pressing force F of the actuators 23A and 23B is given to the floating rollers 12A and 12B via the pressing rollers 19.

Accordingly, the radial escape of the positions of the floating rollers 12A and 12B that is attributable to the pressing force F of the actuators 23A and 23B can be prevented, and the pressing force F of the actuators 23A and 23B can be reliably given to the floating rollers 12A and 12B. The floating rollers 12A and 12B can be held in a very stable manner in their maximum diameter portions by the pair of guide rollers 20 being disposed at the positions (heights) of the orthogonal lines L1 and L2 passing through the axial center lines C1 and C2 of the roller shafts 7A and 7B as described above.

The constant force that changes only the sectional shape of the tapered material M′ without causing its plate thickness to be impaired by the floating rollers 12A and 12B is set as the pressing force F of the actuators 23A and 23B.

Once the constant force is set as the pressing force F of the actuators 23A and 23B as described above, the plate thickness of the tapered material M′ is not impaired and the tapered material M′ is roll-molded into a predetermined sectional shape with its originally planned plate thickness maintained even if the floating rollers 12A and 12B are pressed against the tapered material M′ due to the pressing force F.

Accordingly, the product quality of the aircraft tapered stringer TS or the like can be improved without the plate thickness of each portion of the tapered material M′, which has the plate thickness changing in the tapered shape along the longitudinal direction, being impaired.

The recessed portions for driving 15 and the projecting portions for driving 16 respectively provide fitting between the fixed roller 11A and the floating roller 12A disposed on the roller shaft 7A and between the fixed roller 11B and the floating roller 12B disposed on the roller shaft 7B, and rotation of the fixed rollers 11A and 11B is transmitted to the floating rollers 12A and 12B. In addition, the eccentricity margins EA and EB allowing the floating rollers 12A and 12B to be eccentric are provided between the recessed portions for driving 15 and the projecting portions for driving 16.

As a result, a rotational force of the fixed rollers 11A and 11B integrally disposed on the roller shafts 7A and 7B is transmitted to the floating rollers 12A and 12B because of the fitting between the recessed portions for driving 15 and the projecting portions for driving 16. Accordingly, the roll-moldability of the tapered material M′ can be improved with the floating rollers 12A and 12B reliably driven to rotate without slipping.

Furthermore, since the eccentricity margins EA and EB allowing the floating rollers 12A and 12B to be eccentric are provided between the recessed portions for driving 15 and the projecting portions for driving 16, the floating rollers 12A and 12B can be driven to rotate with eccentricity with respect to the roller shafts 7A and 7B allowed. As a result, the tapered material M′ that has the changing plate thickness can be smoothly molded.

The roller width W of the floating roller 12A can be changed, and thus the width W of the floating roller 12A can match an inside dimension of the metallic material even if the metallic material, such as the tapered material M′, has a sectional shape that includes a recessed portion which has a channel shape or the like. Accordingly, the metallic material can be roll-molded with accuracy.

In the present embodiment, only the floating roller 12A has the roller width W that can be changed. However, the floating roller 12B and the fixed rollers 11A and 11B can have a roller width that can be changed, too.

With the roll-molding device 1 according to the present embodiment, roll-molding can be performed with stability and by the use of the simple and inexpensive configuration as described above even on the tapered material M′ that has the plate thickness changing in the longitudinal direction.

The present invention is not limited to the configuration of each of the embodiments described above, and any appropriate change and improvement can be added thereto without departing from the scope of the present invention. Any embodiment resulting from such changes and improvements is to be included in the scope of rights pertaining to the present invention.

For example, the two roller shafts 7A and 7B can have a variable interaxial distance although the roller shafts 7A and 7B are disposed in a state where the interaxial distance is fixed in the embodiment described above.

In addition, the shape of the tapered material M′ and the shape of the tapered stringer TS molded from the tapered material M′ are not limited to those according to the embodiment described above.

REFERENCE SIGNS LIST

1 Roll-molding device

7A, 7B Roller shaft

11A, 11B Fixed roller

12A, 12B Floating roller

15 Recessed portion for driving

16 Projecting portion for driving

19 Pressing roller

20 Guide roller

21A, 21B Roller carrier

23A, 23B Actuator

CA, CB Clearance

C1, C2 Axial center line of roller shaft

EA, EB Eccentricity margin

F Pressing force of actuator

L1, L2 Orthogonal line orthogonal to axial center connecting line

M′ Metallic material

O Axial center connecting line connecting axial center lines to each other

T1, T2, T3 Plate thickness of metallic material

W Roller width

Z1, Z2 Range between pivotal support position of roller shaft and pivotal support position of pressing roller 

1. A roll-molding device comprising: two parallel roller shafts; a fixed roller concentrically disposed with respect to one of the two roller shafts; a floating roller disposed to be capable of being eccentric with a clearance with respect to the other one of the two roller shafts and facing the fixed roller; a pressing roller abutting against an outer circumferential portion on the side opposite to a point of contact of the floating roller with the fixed roller; and an actuator pressing the floating roller toward the fixed roller via the pressing roller.
 2. The roll-molding device according to claim 1, wherein the pressing roller is disposed in a distributed manner at a plurality of symmetrical positions across an axial center connecting line, which connects axial center lines of the two roller shafts to each other, in axial view of the two roller shafts.
 3. The roll-molding device according to claim 2, wherein the plurality of pressing rollers is pivotally supported by a common roller carrier and the actuator presses a position of intersection of the roller carrier with the axial center connecting line in the axial view of the two roller shafts.
 4. The roll-molding device according to claim 1, further comprising: a pair of guide rollers abutting against the outer circumferential portion of the floating roller and pivotally supported on both sides of the axial center connecting line across the axial center connecting line connecting the axial center lines of the two roller shafts to each other within a range between a pivotal support position of the roller shaft where the floating roller is disposed and a pivotal support position of the pressing roller.
 5. The roll-molding device according to claim 1, wherein a constant force changing only a sectional shape of a metallic material pinched between the fixed roller and the floating roller without impairing a plate thickness of the metallic material is set as a pressing force of the actuator.
 6. The roll-molding device according to claim 1, wherein a plurality of sets of the fixed rollers and a plurality of sets of the floating rollers are disposed, wherein the fixed roller and the floating roller are disposed adjacent to each other in an axial direction at each of the two roller shafts, wherein the fixed roller disposed at each one of the roller shafts faces the floating roller disposed at the other one of the roller shafts, wherein a plurality of recessed portions for driving lining up in a circumferential direction is formed in an adjacent surface of one of the fixed roller and the floating roller adjacent to each other and pivotally supported by one of the roller shafts and a plurality of projecting portions for driving loosely fitted into the recessed portions for driving is formed on the other adjacent surface, and wherein an eccentricity margin allowing the floating roller to be eccentric is provided between the recessed portion for driving and the projecting portion for driving.
 7. The roll-molding device according to claim 1, wherein a roller width of at least one of the fixed roller and the floating roller can be changed. 